Add contributing guide

CONTRIBUTING.md

@@ -0,0 +1,33 @@
+# Contributing to Warden
+
+The Cloud Foundry team uses GitHub and accepts contributions via
+[pull request](https://help.github.com/articles/using-pull-requests).
+
+## Contributor License Agreement
+
+Follow these steps to make a contribution to any of our open source repositories:
+
+1. Ensure that you have completed our CLA Agreement for
+  [individuals](http://www.cloudfoundry.org/individualcontribution.pdf) or
+  [corporations](http://www.cloudfoundry.org/corpcontribution.pdf).
+
+1. Set your name and email (these should match the information on your submitted CLA)
+
+        git config --global user.name "Firstname Lastname"
+        git config --global user.email "your_email@example.com"
+
+## General Workflow
+
+1. Fork the repository
+1. Create a feature branch (`git checkout -b better_warden`)
+1. Make changes on your branch
+1. [Run tests](https://github.com/cloudfoundry/warden#testing)
+1. Push to your fork (`git push origin better_warden`) and submit a pull request
+
+We favor pull requests with very small, single commits with a single purpose.
+
+Your pull request is much more likely to be accepted if:
+
+* Your pull request includes tests
+
+* Your pull request is small and focused with a clear message that conveys the intent of your change

README.md

@@ -45,3 +45,7 @@ The project is licensed under the Apache 2.0 license (see the
 [`LICENSE`][license] file).
 
 [license]: /LICENSE
+
+## Contributing
+
+Please read the [contributors' guide](https://github.com/cloudfoundry/warden/blob/master/CONTRIBUTING.md)